The minimal, futuristic design of the Solari Cifra 3 is timeless. So timeless, in fact, that it's part of the collections of NYC's MoMA and London's Science Museum. So what is it that makes this clock so special?

Designed by Gino Valle in 1965 for Solari di Udine, the cylindrical shape of the Cifra 3 is designed around the shape and movement of the roller blades that display the alphanumeric figures (in Helvetica font, naturally). Not only does the cylindrical shape maximize surface area and minimize volume, the clear front half of the clock lets you see the movement of the clock's mechanical components.

A 1970 ad in New York Magazine said the Cifra 3 sold for $32 back then (which, adjusting for inflation, is probably like spending $200 now). If it sold today, it probably wouldn't be found in a Wal-Mart. [Solari and MoMA]